Re: [dpdk-dev] [DPDK] net/virtio: packed ring notification data feature support

["Liu, Yong" <yong.liu@intel.com>]

> -----Original Message-----
> From: dev <dev-bounces@dpdk.org> On Behalf Of Cheng Jiang
> Sent: Wednesday, December 04, 2019 11:03 PM
> To: dev@dpdk.org
> Cc: maxime.coquelin@redhat.com; Bie, Tiwei <tiwei.bie@intel.com>; Wang,
> Zhihong <zhihong.wang@intel.com>; Jiang, Cheng1 <cheng1.jiang@intel.com>
> Subject: [dpdk-dev] [DPDK] net/virtio: packed ring notification data
> feature support
> 
> This patch supports the feature that the driver passes extra data
> (besides identifying the virtqueue) in its device notifications.
> 
> Signed-off-by: Cheng Jiang <Cheng1.jiang@intel.com>
> ---
>  drivers/net/virtio/virtio_ethdev.h |  3 ++-
>  drivers/net/virtio/virtio_pci.c    | 15 ++++++++++++++-
>  drivers/net/virtio/virtio_pci.h    |  6 ++++++
>  3 files changed, 22 insertions(+), 2 deletions(-)
> 
> diff --git a/drivers/net/virtio/virtio_ethdev.h
> b/drivers/net/virtio/virtio_ethdev.h
> index a10111758..cd8947656 100644
> --- a/drivers/net/virtio/virtio_ethdev.h
> +++ b/drivers/net/virtio/virtio_ethdev.h
> @@ -36,7 +36,8 @@
>  	 1ULL << VIRTIO_F_IN_ORDER        |	\
>  	 1ULL << VIRTIO_F_RING_PACKED	  |	\
>  	 1ULL << VIRTIO_F_IOMMU_PLATFORM  |	\
> -	 1ULL << VIRTIO_F_ORDER_PLATFORM)
> +	 1ULL << VIRTIO_F_ORDER_PLATFORM  |	\
> +	 1ULL << VIRTIO_F_NOTIFICATION_DATA)
> 
>  #define VIRTIO_PMD_SUPPORTED_GUEST_FEATURES	\
>  	(VIRTIO_PMD_DEFAULT_GUEST_FEATURES |	\
> diff --git a/drivers/net/virtio/virtio_pci.c
> b/drivers/net/virtio/virtio_pci.c
> index 4468e89cb..2462a7dab 100644
> --- a/drivers/net/virtio/virtio_pci.c
> +++ b/drivers/net/virtio/virtio_pci.c
> @@ -418,7 +418,20 @@ modern_del_queue(struct virtio_hw *hw, struct
> virtqueue *vq)
>  static void
>  modern_notify_queue(struct virtio_hw *hw __rte_unused, struct virtqueue
> *vq)
>  {

Hi Cheng,
hw pointer will be used in notify function, please remove rte_unused attribute. 

Thanks,
Marvin

> -	rte_write16(vq->vq_queue_index, vq->notify_addr);
> +	uint32_t notify_data;
> +
> +	if (!vtpci_with_feature(hw, VIRTIO_F_NOTIFICATION_DATA)) {
> +		rte_write16(vq->vq_queue_index, vq->notify_addr);
> +		return;
> +	}
> +
> +	if (vtpci_with_feature(hw, VIRTIO_F_RING_PACKED))
> +		notify_data = ((((uint32_t)vq->vq_packed.used_wrap_counter <<
> 15) |
> +				vq->vq_avail_idx) << 16) | vq->vq_queue_index;
> +	else
> +		notify_data = ((uint32_t)vq->vq_avail_idx << 16) |
> +				vq->vq_queue_index;
> +	rte_write32(notify_data, vq->notify_addr);
>  }
> 
>  const struct virtio_pci_ops modern_ops = {
> diff --git a/drivers/net/virtio/virtio_pci.h
> b/drivers/net/virtio/virtio_pci.h
> index a38cb45ad..7433d2f08 100644
> --- a/drivers/net/virtio/virtio_pci.h
> +++ b/drivers/net/virtio/virtio_pci.h
> @@ -135,6 +135,12 @@ struct virtnet_ctl;
>   */
>  #define VIRTIO_F_ORDER_PLATFORM 36
> 
> +/*
> + * This feature indicates that the driver passes extra data (besides
> + * identifying the virtqueue) in its device notifications.
> + */
> +#define VIRTIO_F_NOTIFICATION_DATA 38
> +
>  /* The Guest publishes the used index for which it expects an interrupt
>   * at the end of the avail ring. Host should ignore the avail->flags
> field. */
>  /* The Host publishes the avail index for which it expects a kick
> --
> 2.17.1